Local Government Minister Carl Sargeant paid tribute to the various groups who contributed towards securing the electrification of the railway line between London and Swansea and the Valleys Line on 17 July 2012.
He thanked the Secretary of State for Transport in Westminster, Network Rail, the transport team in Welsh government and the Welsh businesses, AMs, MPs, local authorities and interest groups for their work.
The electrification of the main rail line will reduce the three-hour journey between Paddington and Swansea by 20 minutes.
As well as cutting journey times, new trains will have nine carriages instead of eight, allowing more passengers to be carried on the line.
Conservative AM Byron Davies welcomed the investment totalling £2billion by the UK government as he stressed that this was "key to our economic recovery".
Rhodri Glyn Thomas, Plaid Cymru AM for Dinefwr and Carmarthen West, acknowledged the cross-party efforts to ensure that the electrification was realised.
Liberal Democrat AM Eluned Parrott described the success as a "triumph for co-operation and collaboration".
Read this in Welsh.